DE102004029071B3 - Cups of hybrid materials and process for their preparation - Google Patents

Abstract

Internal combustion engine with bearing shells, which are formed essentially by thermally sprayed bearing layers, wherein the thermally sprayed bearing layers are formed by phases of at least two sliding bearing materials with different hardness, which are spatially separated from each other and arranged on the surface of the bearing shell, and methods for producing bearings for internal combustion engines, comprising the steps:
- Mechanical conditioning of the bearing surface
- Coating the bearing surface with the material of the bearing shell by means of thermal spraying
- smoothing finish of the sprayed on layer,
wherein as a bearing shell at least two sliding bearing materials are deposited with different hardness in spatially separated areas, the materials are in contact with each other via mixed structure.

Description

The Invention relates to an internal combustion engine with bearing shells, by thermally sprayed bearing layers made of different materials are formed, and method for producing bearings for internal combustion engines comprising the steps of mechanically conditioning the bearing surface, coating the bearing surface with the material of the bearing shell by means of arc wire spraying, atmospheric plasma spraying or high speed flame spraying, and smoothing finish of the sprayed Layer. The invention particularly relates to bearing shells, which in a connecting rod are arranged.

camp in internal combustion engines are usually designed as plain bearings. The Bearing loads typically have a force preferred direction. In addition to the carrying capacity in this force preferred direction also sets the dirt embedding ability of the bearing material is an essential requirement for the sliding bearing Preferably, therefore, with regard to the bearing load in Force direction a very viable Stock layer selected be and contrary to the load direction a very dirty tolerant Storage layer be present. This is typically a split Bearing shell arrangement selected, which differ by two in the bearing insertable half shells Material is formed. These are divided into the storage Motor structure introduced and bolted to the corresponding bearing clearance.

The bearing layers are usually applied directly to the substrate material. So is for example from the DE 197 31 625 A1 a connecting rod is known, which has a bearing layer with a layer thickness between 150 to 800 microns. The bearing layer is applied by means of thermal spraying, in particular by means of plasma spraying and consists of a metal alloy, optionally in combination with dry lubricants.

From the DE 100 350 32 A1 a method for producing a connecting rod with a bearing layer is known, wherein the bearing layer is preferably applied by means of thermal spraying, in particular plasma spraying or electric arc wire spraying and preferably consists of Al / Cu alloys or Cu / (Zn, Al, Sn) alloys.

From the DE 100 35 031 A1 are also known by thermal spraying sliding bearing layers known. In this case, the plain bearing layers have a gradual change in the composition of the coating with increasing layer thickness. Preferably, the coating is close to the substrate mainly of CuAl alloy and substrates far removed auszunehmenden proportions of titanium oxide.

From the DE 39 05 450 C2 are plain bearings with a support layer on which an intermediate layer is known. The intermediate layer has mutually spaced groove portions at least on a part of the bearing periphery which are filled with a lubricious layer-forming material softer than the material of the intermediate layer, optionally providing a diffusion or bonding layer on the surface of the groove portions.

From the US 62 73 612 B1 Bearings for internal combustion engines are known, the bearing layers are formed by phases of two sliding bearing materials with different hardness. These are spatially separated from each other and arranged on the surface of the bearing shell.

From the DE 198 24 308 C1 are known bearing shells whose metallic overlays are formed of a matrix material and a finely dispersed therein component with a higher atomic weight. The finely dispersed component has a concentration gradient. The sliding layer is applied by means of electron beam vapor deposition.

In the EP 0 272 447 B1 discloses a composite material having a sputtered spin-on layer. This is formed by a metallic matrix and at least one further metallic material practically insoluble in the matrix. The diameter of the particles of the insoluble material has a gradient parallel to the surface of the sliding layer, which corresponds to a hardness gradient of the sliding layer.

From the DE 36 21 577 is a sliding bearing with a base layer of bearing material is known, which has axially spaced groove-like recesses, which are preferably filled with a sliding bearing material with respect to the bearing material of the support layer of different hardness.

From the DE 3 31 379 C are known bearings whose bearing surfaces are produced by spraying molten or vaporized bearing metal.

The lead known methods partly too. Storage layers with a same over the entire bearing surface Property profile or are partly technically complex.

It is therefore an object of the invention bearing provide layered bearing shells, which can meet the different requirements in terms of carrying capacity and dirt tolerance according to local requirements, and a method for producing these storage layers.

• – mechanisches Konditionieren der Lageroberfläche
• – Beschichten der Lageroberfläche mit dem Material der Lagerschale mittels Lichtbogendrahtspritzen, atmosphärischem Plasmaspritzen oder Hochgeschwindigkeitsflammspritzen
• – glättende Endbearbeitung der aufgespritzten Schicht mit den kennzeichnenden Merkmalen des Anspruchs 11.

The object is achieved by an internal combustion engine with bearing shells, which are formed essentially by thermally sprayed bearing layers with the characterizing features of claim 1, and with a method for producing bearing shells for internal combustion engines comprising the steps:

• - Mechanical conditioning of the bearing surface
• - Coat the bearing surface with the material of the bearing shell by means of arc wire spraying, atmospheric plasma spraying or high-speed flame spraying
• - Smoothing finishing of the sprayed layer with the characterizing features of claim 11.

Consequently The thermally sprayed bearing layers are inventively by Phases of at least two sliding bearing materials with different Hardness formed, where the phases are spatial separated from each other. Here are the phases of at least two sliding bearing materials arranged on the surface of the bearing shell, so that the corresponding phases in the sliding layer tribological are active.

Of the Material of the bearing layers according to the invention with a distribution of spatial separate phases of at least two sliding bearing materials is referred to below as a hybrid material. It is essential that the individual sliding bearing materials in their Hardness of each other differ. At least two of the sliding bearing materials should be in terms of their hardness clearly different from each other.

By The hybrid material is a sliding layer formed, both the properties for one viable Layer as well as the properties of the dirt tolerance.

there These specific properties are essentially determined by the Hardness of corresponding sliding bearing materials determined, the harder component of the hybrid material for the carrying capacity and the softer component for the dirt tolerance ensures. Due to the material combination in one Hybrid material, the individual properties are mutually Cheap affected.

According to the invention the contiguous phases of the at least two sliding bearing materials through a mixed structure separated from each other, which are the elements of different sliding bearing material includes. This is a very homogeneous transition between the different materials and in particular their physical properties ensured. Likewise, the phases of the different materials are very strong connected with each other. This also results in good adhesion on the substrate, which is particularly advantageous under tribological and temperature cycling proves.

The Phases of different sliding bearing materials form at the surface area Structures out. This ensures that all materials involved are also effective in the tribologically stressed sliding zone.

In A first embodiment of the invention becomes macroscopic planar structures educated. By macroscopic structures is meant that the individual phases, or those on the surface of the flat Structures arranged phases have an area above about 1 mm ^ 2. Preferably, the length is and / or the width at the surface above 5 mm. These structures can do this irregular shape, preferred but roundish, elongated or linear Have shape.

Prefers show the elongated ones or linear Embodiments preferred directions, particularly preferably in concentric Circles or spirals or axially to the center axis of the plain bearing. In this case, the length is and / or width of the structures in the region of the outer dimensions of the sliding bearing.

In Another embodiment of the invention are instead of the macroscopic microscopic structures. This means that the different Phases form a microscopic mixed structure. The dimensions The structures are thus in the range of typical metallic mixed crystal structure.

Independent of the geometrical configuration, the sliding bearing by at least two different sliding bearing materials are formed, one of which at least two differ significantly in their hardness from each other.

The hard bearing materials are in particular selected from one of the following types of alloys:
Brass, for example CuZn31Si1,
Al-bronze, for example
Al / Cu alloy, for example
Zn-based bronze, for example
Sn-based bronze, for example
and / or Pb-based bronze, for example

The soft bearing materials are in particular selected from one of the following types of alloys:
Bronze, for example CuSn6Ag1
Zn-based white metal, for example
Pb-based white metal, for example
Pb-based bronze, for example
Bronze on Pb / Sn basis, for example
Al / Sn alloy, for example
For example, Pb / Sn alloy
and / or gunmetal, for example

The Hardness of to be selected according to the invention Plain bearing materials is in the usual for these materials Areas. The hardness is preferred soft bearing materials at 20 ° C in the range of 20 to 80 HB and the hardness Hard bearing materials in the range of 80 to 200 HB.

Differ according to the invention The sliding bearing materials with respect to their hardness from each other. The difference between the hardness (reference temperature 20 ° C) is preferred the softest and the hardest Sliding bearing material of the bearing layer above 30 HB. Especially preferred a difference of at least 50 HB is chosen.

at the selection of the sliding bearing materials, it is also advantageous when formed from closely related alloying systems become. This favors a firm connection between the different phases. A preferred combination is brass made of CuZn31Si1 and bronze formed from CuSn6Ag1.

ever According to load and application, the quantity ratio of different sliding bearing materials on the bearing shell evenly or locally distributed very differently. That can for example mean that the plain bearing on the side of the force application predominantly from the harder sliding bearing material and on the other hand predominantly is formed from the weeping.

About the Entity of the bearing shell is the ratio of soft to hard Sliding bearing material according to the invention, however, at 1:10 to 10: 1. Prefers at least that's the ratio the hardest to the softest material close to 1: 1, especially at 0.8 to 1.2.

The surface the bearing shell is typically smoothed and can contain microcompartments, For example, in cup or channel shape. Microcompartments that for holding and as a reservoir for liquid lubricants act, are known in principle. An inventive embodiment the surface the bearing shell provides that the number or area of the Microcompartments for soft and hard bearing material is chosen differently. In this case, preferably, the hard material has a higher number of microcompartments if necessary, the soft material may not have any May have microcompartments.

• – mechanisches Konditionieren der Lageroberfläche
• – Beschichten der Lageroberfläche mit dem Material der Lagerschale durch thermische Spritzverfahren
• – glättende Endbearbeitung der aufgespritzten Schicht, wobei als wesentliches Verfahrensmerkmal mindestens zwei Gleitlagerwerkstoffe mit unterschiedlicher Härte in räumlich voneinander getrennten Bereichen abgeschieden werden, wobei. die Werkstoffe über Mischgefüge miteinander in Kontakt stehen.

Another aspect of the invention relates to a preferred manufacturing method for the bearing shells according to the invention. The method for manufacturing bearing shells for internal combustion engines comprises the following steps:

• - Mechanical conditioning of the bearing surface
• - Coating the bearing surface with the material of the bearing shell by thermal spraying
• - Smoothing finishing of the sprayed layer, being deposited as an essential process feature at least two sliding bearing materials with different hardness in spatially separated areas, wherein. the materials are in contact with each other via mixed structure.

The Mechanical conditioning of the surface is typically one Roughening, for example by sandblasting, water jetting, surface grinding or vibratory grinding.

To the preferred thermal spray processes include arc wire spraying, atmospheric Plasma spraying or high-speed flame spraying.

method of the generic type are known. In such a thermal coating, for example a plasma coating, is a coating material, in particular a metal, supplied in powder or rod form a flame, in this melted and deposited on the surface to be coated. Depending on used coating material and ambient atmosphere used can coatings with different properties, in particular with desired Sliding properties, hardness properties, layer thicknesses or the like can be achieved.

In A preferred embodiment of the invention is a thermal Spray method or one for this adapted spray device selected the simultaneous separation of the different sliding bearing materials enable. These include spray devices with several spray nozzles.

Likewise, it is also possible in the injection process, a powder mixture of different Components, or different spray wires or a filler or composite wire to use by spraying.

The Sliding bearing materials are preferred in a layer thickness in the range from 0.1 to 2.5 mm.

In In another embodiment, recesses are made in the bearing shell introduced in the form of microcompartments. This can be done by the usual methods preferably by means of laser irradiation or chemical etching.

Claims (15)

Bearing shells, which are formed essentially by thermally sprayed bearing layers, characterized in that the thermally sprayed bearing layers are formed by phases of at least two sliding bearing materials with different hardness, which are spatially separated from each other and arranged on the surface of the bearing shell. Bearing shells according to claim 1, characterized in that that the adjoining phases of the at least two sliding bearing materials separated by a mixed phase, which are the elements includes the different sliding bearing materials. Bearing shells according to claim 1 or 2, characterized that the phases of the at least two sliding bearing materials at the surface area Structures form the roundish, oblong or linear shape have, with the elongated or linear Structures preferably in concentric circles or spirals or run axially. Bearing shells according to claim 3, characterized in that that the surface the single plane Structures above 1 mm ^ 2 lies. Bearing shells according to one of the preceding claims, characterized characterized in that the hard sliding bearing materials are selected made of brass, Al-bronze, Al / Cu alloy, Zn-based bronze, bronze Sn-based and / or Pb-based bronze. Bearing shells according to one of the preceding claims, characterized characterized in that the soft sliding bearing materials are selected made of white metal Zn-based, white metal Pb-based, Pb-based bronze, Pb / Sn-based bronze, Al / Sn alloy, Pb / Sn alloy and / or gunmetal. Bearing shells according to one of the preceding claims, characterized characterized in that the difference in hardness at 20 ° C between the softest and the hardest Sliding bearing material of the bearing layer is above 30 HB. Bearing shells according to one of the preceding claims, characterized characterized in that the hardness of the soft plain bearing materials in the range of 20 to 80 HB at 20 ° C and the Hardness of Hard bearing materials in the range of 80 to 200 HB at 20 ° C. Bearing shells according to one of the preceding claims, characterized characterized in that the ratio from soft to hard bearing material of the entire bearing shell at 1:10 to 10: 1. Bearing shells according to one of the preceding claims, characterized characterized in that the bearing cup microcompartments in cup or Has channel shape. Method for producing bearing shells for internal combustion engines comprising the steps: - mechanical Conditioning the bearing surface - coating the bearing surface with the material of the bearing shell by means of thermal spraying - smoothing finishing the sprayed-on layer, characterized in that when Bearing shell at least two plain bearing materials with different Hardness in spatial separated from each other, wherein the Materials over mixed structure in contact with each other. Method according to claim 11, characterized that as a thermal spraying process the arc wire spraying is used, wherein at least one filler wire or a composite wire used which covers the different sliding bearing materials. Method according to claim 11 or 12, characterized that the sliding bearing materials in a layer thickness in the range of 0.1 to 2.5 mm are deposited. Method according to one of Claims 12 to 13, characterized that the conditioning by high-pressure water jetting or sandblasting he follows. Method according to one of claims 11 to 14, characterized that in the bearing shell recesses in the form of microcompartments by laser irradiation or chemical etching be introduced.